The invention relates to a nozzle tip of special construction mounted an the barrel of a standard syringe for dispensing bone regeneration materials to a surgical site. The nozzle tip and syringe are used to aspirate marrow blood from a surgical site; then mixing the collected blood marrow with granular bone regeneration material stored in the barrel of the syringe to form a viscous fluid mixture therein; then manually removing the nozzle tip from the syringe barrel; and then dispensing the viscous fluid mixture to the surgical site by manual application of pressure on the plunger of the syringe. Bone regeneration materials are known in the art. For example, hard-tissue implant materials are known, such as the calcified microporous co-polymer bone regeneration material marketed under the trademarks Bioplant(copyright) HTR(copyright) Synthetic Bone(trademark) alloplast. The aforesaid bone regeneration material has been widely accepted in medicine, dentistry and veterinary medicine as a prostethic bone material to repair injured or diseased bone. The followig co-invented U.S. patents describe the use of such bone generation materials: U.S. Pat. Nos. 4,199,864; 4,244,689; 4,535,485; 4,536,158; 4,547,327; 4,547,390 and 4,728,570. The aforelisted co-invented U.S. patents are incorporated by reference herein. For many applications of said Bioplant(copyright), HTR(copyright) bone regeneration material the application of this material in granular form has proven to have many advantages. For example, granular Bioplant(copyright), HTR(copyright) bone regeneration material has proven particularly useful in a tooth extraction procedure. A simple injection of granular Bioplant(copyright), HTR(copyright) bone regeneration material into the tooth socket, following immediately after extraction of the tooth, either significantly reduces or completely prevents the usual 40% to 60% percent bone loss that otherwise occurs within 2-3 years after tooth extraction, and eliminates much of the pain and inflammation of the tooth socket (post-extraction alveolar osteitis). Granular Bioplant(copyright), HTR(copyright) bone regeneration material works best when it is thoroughly wetted with marrow blood before being applied to a surgical site.
It is an object of the present invention to provide a simple improved syringe and nozzle tip construction for producing and then dispensing a viscous mixture of granular Bioplant(copyright), HTR(copyright) bone regeneration material and marrow blood, obtained from a surgical site.
It is another object of the invention to provide a simple method of mixing aspirated marrow blood from a surgical site with granular bone regeneration material inside the barrel of a syringe and, by the use of an improved nozzle tip construction, mounted on a standard syringe, prevent excessive loss of marrow blood and/or granular bone regeneration material during the mixing operation.
It is another object of this invention to provide an aseptic method for mixing aspirated marrow blood from a surgical site with granular bone regeneration material and then applying, in an aseptic manner, the viscous mixture obtained by the mixing in the sterile syringe barrel to the surgical site.
Low density polyethylene has been found to be particularly advantageous for manufacturing the entire nozzle tip construction including the filter screen which is mounted inside the nozzle tip. The openings of the mesh screen must be smaller than the grain size of the granular bone regeneration material inside the syringe barrel. A mesh opening size of about 105 microns has been found to work best with the method of the invention because it can be used with several standard granular sizes of Bioplant(copyright), HTR(copyright) bone regeneration materials.
Further details regarding the nozzle tip construction and the method of forming a viscous mixture of granular Bioplant(copyright) HTR(copyright) polymer material and then applying it to a surgical site will be provided in the followig description of preferred embodiments in conjunction with the accompanying drawings.